"Weissenborns built from 1913 to 1916 have no brands or markings, except for a few that were marketed under department store private labels. From 1916 though 1921, Hermann Weissenborns picture label in appeared in the guitars. The Weissenborn Co. Ltd. factory opened in January 1922, using the burned-brand (like the one in your guitar). Factory guitars were built in 4 styles: 1--no trim, 3 sound hole rings; 2--black binding; 3--rope binding top only; 4--rope binding top and bottom. The factory guitars from 1922-1926 are lightly braced and have a bridge that is 6-3/4 inches from point to point. The factory guitars from 1927-1937 are heavily braced and have bridges that are 5-1/2 inches point to point. The shorter bridges are a spotting feature for me.
From my standpoint, the 1922-1926 factory guitars sound better than the 1927-1937 because they vibrate more, giving that long sustain and ethereal Weissenborn sound. The post 1927 guitars were modified to compete against other instruments in a band setting, and so they are louder but the vibration damps out pretty quick."